Seibu Lions left-hander Koji Mitsui was formally put up for auction under the posting system Thursday.
The deadline for bids from major league clubs is 5 p.m. Tuesday EST, and contract talks can begin once Seibu accepts the highest bid.
Mitsui has a 36-19 career record with a save and a 4.41 ERA in 263 games over eight seasons, all with the Lions. In 2008, the 35-year-old went 1-1 with a 7.50 ERA in 23 relief appearances.